Jewel

ABSTRACT

[Problem] The purpose of the present invention is to provide a jewel on which cuts with excellent symmetry are made, such cuts having originality, exceling aesthetically, and being novel. [Solution] A diamond ( 1 ), serving as a jewel, is cut so as to have a crown ( 3 ) provided with a table ( 2 ), and a pavilion ( 5 ) provided with a culet ( 4 ). By creatively modifying the shape and disposition of a main facet ( 8 ) formed in the pavilion ( 5 ), the diamond ( 1 ) is configured so that a heart pattern can be made to appear when the diamond ( 1 ) is viewed from the table ( 2 ) side.

BACKGROUND OF INVENTION

1. Field of the Invention

The present invention relates to a jewel having cuts formed thereon, thecuts having originality and excelling aesthetically.

2. Description of the Related Art

Jewelry, especially diamond, having a cut called “round brilliant cut”formed thereon has been known to the public. FIG. 1 depicts a diamond 1having the “round brilliant cut” formed thereon. FIG. 1A is a plan viewof the diamond 1, FIG. 1B is a bottom plan view of the diamond 1, andFIG. 1C is a side view of the diamond 1. As shown in FIG. 1, the diamond1 includes a crown 3 having a table (upper plane) 2, a pavilion 5 havinga curette 4, and a girdle 6, which is cut into a round shape between thecrown 3 and the pavilion 5.

In general, on a jewel cut into a cut pattern, a curette is formed as atiny facet that prevents the chipping of the top end of a pavilion. Inthis specification and claims pertaining to the present invention,however, the top end of a pavilion not formed as a facet but as apointed apex (pointed curette), as shown in FIG. 1, is also described asa curette.

Some diamonds 1 having the above cut formed thereon are particularlyexcellent in cut symmetry. It is known that when observing such adiamond 1 from above (from the table 2 side shown in FIG. 1A), one cansee eight arrows 7, as shown in FIG. 2. The arrows 7 are visible to thenaked eyes, and can be seen more clearly using a gemological microscopedescried in Japanese Patent Application Laid-Open Publication No.06-174648 (patent document 1), Japanese Unexamined Patent ApplicationPublication No. 2010-201043 (patent document 2), etc.

Since the arrows 7 can be seen only on the jewel with particularlyexcellent cut symmetry, the visibility of the arrows 7 is widely used asa means for proving the high quality of a jewel. Meanwhile, the roundbrilliant cut is widely recognized as one of completed jewelry cuttechniques. Hence the visibility of the eight arrows 7 is well knowntoday as a feature of a quality jewel.

Various jewels showing patterns different from the eight arrows 7 havebeen proposed. For example, patent document 2 discloses a diamondshowing a heart pattern as well as arrows, as visually recognizablepatterns, and Japanese Unexamined Patent Application Publication No.2004-299370 (patent document 3) discloses a diamond showing not eightbut ten arrows as a visually recognizable pattern. The inventor of thepresent invention proposed a jewel showing a cross pattern as a visuallyrecognizable pattern, disclosing the jewel in Japanese Unexamined PatentApplication Publication No. 2008-541800 (patent document 4).

Under such circumstances, the inventor has studied diligently on how tofabricate a novel diamond having cuts with excellent symmetry formedthereon, the diamond having originality and excelling aesthetically. Thestudy has led to a piece of knowledge that a totally new diamond havingthe above features can be fabricated by modifying the shape anddisposition of main facets formed on the pavilion, thus allowing theinventor to bring about the present invention. The inventor hasconfirmed that the invention apply also to jewels other than diamond.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a jewel having novelcuts with excellent symmetry formed thereon, such cuts havingoriginality and excelling aesthetically.

In order to achieve the object of the present invention, a jewelaccording to the present invention includes a crown having a table, apavilion having a curette, and a girdle formed between the crown and thepavilion. The pavilion has four or more main facets all or some of whichare of triangles, quadrangles, or polygons each having six or moreangles. All the main facets are formed such that in each main facet, thedistance between the curette and the apex of an angle of the main facet,the angle being closest to the girdle, is less than 90% of the distancebetween the curette and the girdle. The main facets are arranged suchthat they are line symmetry with respect to an axis of symmetry which isat least one of lines passing through the curette to bisect thepavilion.

A jewel according to the present invention includes a crown having atable, a pavilion having a curette, and a girdle formed between thecrown and the pavilion. The pavilion has six or more main facets all orsome of which are of polygons each having three or more angles. All themain facets are formed such that in each main facet, the distancebetween the curette and the apex of an angle of the main facet, theangle being closet to the girdle, is less than 90% of the distancebetween the curette and the girdle. The main facets are arranged suchthat they are line symmetry with respect to an axis of symmetry which isat least one of lines passing through the curette to bisect thepavilion.

A jewel according to the present invention includes a crown having atable, a pavilion having a curette, and a girdle formed between thecrown and the pavilion. The pavilion has eight or more main facets allor some of which are of quadrangles each having interior angles alldifferent from each other or of polygons each having five or moreinterior angels all different from each other. All the main facets areformed such that in each main facet, the distance between the curetteand the apex of an angle of the main facet, the angle being closest tothe girdle, is less than 90% of the distance between the curette and thegirdle. The main facets are arranged such that they are line symmetrywith respect to an axis of symmetry which is at least one of linespassing through the curette to bisect the pavilion.

A jewel according to the present invention includes a crown having atable, a pavilion having a curette, and a girdle formed between thecrown and the pavilion. The pavilion has eight main facets made up offour first main facets that are of pentagons each having interior angelsall different from each other and four second main facets that are ofpentagons line symmetrical to the pentagons serving as the first mainfacets. The first main facets and the second main facets are arrangedalternately on the pavilion. Each of the pentagons serving as the firstmain facets and the second main surfaces is formed such that thedistance between the curette and the apex of an angle of the pentagon,the angle being closest to the girdle, is less than 90% of the distancebetween the curette and the girdle.

A jewel according to the present invention includes a crown having atable, a pavilion having a curette, and a girdle formed between thecrown and the pavilion. The pavilion has ten main facets made up of fivefirst main facets that are of pentagons each having interior angels alldifferent from each other and five second main facets that are ofpentagons line symmetrical to the pentagons serving as the first mainfacets. The first main facets and the second main facets are arrangedalternately on the pavilion. Each of the pentagons serving as the firstmain facets and the second main surfaces is formed such that thedistance between the curette and the apex of an angle of the pentagon,the angle being closest to the girdle, is less than 90% of the distancebetween the curette and the girdle.

The jewel according to the present invention is a diamond.

The present invention offers a jewel having novel cuts with excellentsymmetry formed thereon, such cuts having originality and excellingaesthetically.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows external views of a diamond having a round brilliant cutformed thereon;

FIG. 2 is a diagram showing a state of appearance of arrows 7;

FIG. 3 is a diagram showing a state of appearance of the arrows 7;

FIG. 4 is a diagram showing reflected light images R created by mainfacets 8;

FIG. 5 is a diagram showing a path of light passing through a diamond 1;

FIG. 6 is a diagram showing the principle of appearance of the arrows 7;

FIG. 7 is a diagram showing the principle of appearance of the arrows 7;

FIG. 8 shows external diagrams of a diamond 1 according to an embodimentof the present invention;

FIG. 9 depicts a photograph of a heart pattern;

FIG. 10 is a diagram showing a state of appearance of a hear pattern 13;

FIG. 11 is a diagram showing the principle of appearance of the hearpattern 13;

FIG. 12 is a diagram showing the principle of appearance of the hearpattern 13;

FIG. 13 is a diagram showing the principle of appearance of the hearpattern 13;

FIG. 14 is a diagram showing the principle of appearance of the hearpattern 13;

FIG. 15 is a diagram showing the principle of appearance of the hearpattern 13;

FIG. 16 is a diagram of a pavilion 5 for causing a four-leaf cloverpattern to appear;

FIG. 17 is a diagram showing a state of appearance of the four-leafclover pattern;

FIG. 18 depicts a photograph of the four-leaf clover pattern;

FIG. 19 is a diagram of the pavilion 5 for causing a peach blossompattern to appear;

FIG. 20 is a diagram showing a state of appearance of the peach blossompattern;

FIG. 21 depicts a photograph of the peach blossom pattern;

FIG. 22 is a diagram of the pavilion 5 for causing a cherry blossompattern to appear;

FIG. 23 is a diagram showing a state of appearance of the cherry blossompattern;

FIG. 24 depicts a photograph of the cherry blossom pattern;

FIG. 25 is a diagram of the pavilion 5 for causing a butterfly patternto appear;

FIG. 26 is a diagram showing a state of appearance of the butterflypattern;

FIG. 27 is a diagram of the pavilion 5 for causing a pattern of theHouse of Takeda's family crest (takeda-bishi) to appear;

FIG. 28 is a diagram showing a state of appearance of the pattern of theHouse of Takeda's family crest (takeda-bishi);

FIG. 29 is a diagram of the pavilion 5 for causing a narcissus blossompattern to appear;

FIG. 30 is a diagram showing a state of appearance of the narcissusblossom pattern;

FIG. 31 shows diagrams of the diamond 1 having a square girdle 6;

FIG. 32 shows diagrams of the diamond 1 having an elliptic girdle 6; and

FIG. 33 depicts the principle of appearance of the reflected lightimages R in a four-leaf clover pattern.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of a jewel according to the present invention willhereinafter be described. It is confirmed that understanding theprinciple of appearance of arrows in a diamond having a conventionalround brilliant cut formed thereon, particularly, understanding theprinciple of appearance of the shaft portions of the arrows will be agreat help in understanding the present invention. For this reason, theprinciple of appearance of the shaft portions of the arrows will firstbe described.

FIG. 1 depicts a diamond 1 having the round brilliant cut formedthereon. FIG. 1A is a plan view of the diamond 1, FIG. 1B is a bottomplan view of the diamond 1, and FIG. 1C is a side view of the diamond 1.As shown in FIG. 1, the diamond 1 includes a crown 3 having a table(upper plane) 2, a pavilion 5 having a curette 4, and a girdle 6 cutinto a round shape between the crown 3 and the pavilion 5. In FIG. 1B, 8denotes eight main facets formed on the pavilion 5, and 9 denotes 16lower girdle facets formed on the pavilion 5.

FIG. 2 depicts a state of appearance of eight arrows 7 in a case wherethe diamond 1 is observed from above (table 2 side shown in FIG. 1A).Each arrow 7 is composed of a shaft portion 7 a and an arrowhead portion7 b. As shown in FIG. 2, the shaft portions 7 a are visually recognizedinside the table 2. In the following description of the principle ofappearance of the shaft portions 7 a, the vicinity of the bases of thearrows 7, i.e., the vicinity of the center of the diamond 1, which isrendered invisible in the end by light reflected on the diamond 1, willbe treated, for convenience, as a visually recognizable pattern, asshown in FIG. 3.

The shaft portions 7 a visually recognized inside the table 2 arecreated by reflected light images R on the main facets 8, as shown inFIG. 4. The shape of the arrowhead portions 7 b of FIG. 3 is differentfrom the shape of the corresponding portions of the reflected lightimages R of FIG. 4. This is because that the arrowhead portions 7 b arecreated by reflected light including a portion of reflected light (notdepicted) not making up the reflected light images R. Describing aportion of reflected light not making up the reflected light images R isconsidered to be unnecessary, and is therefore omitted.

The reflected light images R on the main facets 8 are created basicallyby the following process. As shown in FIG. 5, light L falls onto a facet10 on the crown 3 of the diamond 1 and travels toward its interior.Being affected by the inclination of the facet 10 and the refractiveindex of the diamond 1, light L is reflected consecutively at a firstreflection point 11 and a second reflection point 12. Reflected light Lthen travels outward from inside the table 2 to come out of the diamond1.

FIG. 6 depicts the above reflection of light occurring twice on thepavilion 5. As shown in FIG. 6, light reflected on a main facet 8 a,where the first reflection point 11 is present, is then reflected on amain facet 8 b, which is opposite to the main facet 8 a with respect tothe curette 4 and where the second reflection point 12 is present.

The main facet 8 a and the main facet 8 b face each other in their slantpositions. This causes a reflected light image R on the main facet 8 bto contract mainly in its longitudinal direction (horizontal directionin FIG. 6), as shown in FIG. 6. As a result, the reflected light image Rbecomes smaller in shape than the main facet 8 b.

The light reflection process as described above occurs on all of theeight main facets 8, as shown in FIG. 7. When the reflected light imagesR created in such a manner are observed from above the diamond 1, theshaft portions 7 a of the eight arrows 7 are visually recognized insidethe table 2. This is the principle of appearance of the shaft portions 7a of the arrows 7 on the diamond having the conventional round brilliantcut formed thereon.

An embodiment of the present invention will then be described. FIG. 8depicts a diamond 1 provided as a jewel according to the presentinvention. FIG. 1A is a plan view of the diamond 1, and FIG. 1B is abottom plan view of the diamond 1. Similar to the diamond having theconventional round brilliant cut formed thereon, the diamond 1 of thisembodiment is cut in such a way as to include the crown 3 having thetable 2 and the pavilion 5 having the curette 4. This diamond 1 includesalso the girdle cut into a round shape (not depicted) between the crown3 and the pavilion 5, as the diamond having the round brilliant cutdoes.

As shown in FIG. 8B, modifying the shape and disposition of the mainfacets 8 formed on the pavilion 5 allows the diamond 1 of thisembodiment to cause a pattern different from a conventional arrowpattern to appear. FIG. 9 depicts a photograph of the diamond 1 of thisembodiment that is taken from above the diamond 1 (table 2 side shown inFIG. 8A) using a gemological microscope. A pattern visually recognizedon the diamond 1 of FIG. 8 imitates a heart shape. The principle ofappearance of such a heart pattern will hereinafter be described.

FIG. 10 depicts a state of appearance of a heart pattern 13 in a casewhere the diamond 1 is observed from above. As shown in FIG. 10, theheart pattern 13 is visually recognized inside the table 2.

The heart pattern 13 visually recognized inside the table 2 is createdby the reflected light images R on the main facets 8 formed on thepavilion 5, as shown in FIG. 11. The reflected light images R arecreated basically by the following process. As shown in FIG. 5, light Lfalls onto the facet 10 on the crown 3 of the diamond 1 and travelstoward its interior. Being affected by the inclination of the facet 10and the refractive index of the diamond 1, light L is reflectedconsecutively at the first reflection point 11 and the second reflectionpoint 12. Reflected light L then travels outward through the table 2 tocome out of the diamond 1.

FIG. 12 depicts the above reflection of light occurring twice on thepavilion 5. As shown in FIG. 12, light reflected on the main facet 8 a,where the first reflection point 11 is present, is then reflected on themain facet 8 b, which is opposite to the main facet 8 a with respect tothe curette 4 and where the second reflection point 12 is present.

The main facet 8 a and the main facet 8 b face each other in their slantpositions. This causes a reflected light image R on the main facet 8 bto contract mainly in its longitudinal direction (horizontal directionin FIG. 12), as shown in FIG. 12. As a result, the reflected light imageR becomes smaller in shape than the main facet 8 b.

The light reflection process as described above occurs on each of themain facets 8 a and 8 b different in size and shape from each other, asshown in FIGS. 13 to 15. When all the reflected light images R createdin such a manner are observed from above the diamond 1, the heartpattern 13 shown in FIG. 10 is visually recognized. According to theabove described principle, the diamond 1 of this embodiment causes theheart pattern 13 to appear.

In the embodiment described above, the shape and disposition of facetson the crown 3 are specified (see FIG. 8A). However, according to thepresent invention, what pattern is to appear is determined by the shapeand disposition of the main facets 8. The shape and disposition of thefacets on the crown 3 are therefore not limited to specific shape anddisposition. If at least the table 2 and the facets with the sameinclination as the conventional one (e.g., inclination of 31 degree to36 degrees for the case of diamond) are formed on the crown 3, such acrown 3 is considered to be applicable.

For example, by forming the main facets 8 on the pavilion 5 in such amanner as shown in FIG. 16, a pattern imitating a four-leave clover, asshown in FIG. 17, is caused to appear, which is visually recognized whenthe diamond is seen from the table 2 side. FIG. 18 depicts a photographof this four-leave clover pattern that is taken from the table 2 sideusing a gemological microscope. For reference, the principle ofappearance of the reflected light images R making up the four-leaveclover pattern is indicated simply in FIGS. 33A and 33B.

By forming the main facets 8 on the pavilion 5 in such a manner as shownin FIG. 19, a pattern imitating a peach blossom, as shown in FIG. 20, iscaused to appear, which is visually recognized when the diamond is seenfrom the table 2 side. FIG. 21 depicts a photograph of this peachblossom pattern that is taken from the table 2 side using a gemologicalmicroscope.

By forming the main facets 8 on the pavilion 5 in such a manner as shownin FIG. 22, a pattern imitating a cherry blossom, as shown in FIG. 23,is caused to appear, which is visually recognized when the diamond isseen from the table 2 side. FIG. 24 depicts a photograph of this cherryblossom pattern that is taken from the table 2 side using a gemologicalmicroscope.

By forming the main facets 8 on the pavilion 5 in such a manner as shownin FIG. 25, a pattern imitating a butterfly, as shown in FIG. 26, iscaused to appear, which is visually recognized when the diamond is seenfrom the table 2 side. In FIG. 26, lines on the crown 2 are notdepicted.

By forming the main facets 8 on the pavilion 5 in such a manner as shownin FIG. 27, a pattern imitating the House of Takeda's family crest(takeda-bishi), as shown in FIG. 28, is caused to appear, which isvisually recognized when the diamond is seen from the table 2 side. InFIG. 28, lines on the crown 2 are not depicted.

By forming the main facets 8 on the pavilion 5 in such a manner as shownin FIG. 29, a pattern imitating a narcissus blossom, as shown in FIG.30, is caused to appear, which is visually recognized when the diamondis seen from the table 2 side. In FIG. 30, lines on the crown 2 are notdepicted.

In each of the above examples, the main facets 8 are formed in a mannerdifferent from a manner in which the main facets of the diamond havingthe conventional round brilliant cut are formed. Specifically, the mainfacets 8 in each example do not extend up to a position in contact withthe girdle. The main facets 8 are formed in this manner because if themain facets 8 extend up to the position in contact with the girdle, thefront ends of reflected light images R that are closer to the girdle areconcealed by the facets on the crown 3 when the reflected light images Rare seen from the table side, in which case an overall view of thereflected light images R cannot be seen inside the table. For thisreason, in each of the above examples, every main facet 8 is formed suchthat the distance between the curette 4 and the apex of an angle of themain facet 8 (e.g., apex 8P of FIG. 8B), the angle being closest to thegirdle 6, is less than 90% of the distance between the curette 4 and thegirdle 6.

In each of the above examples, the diamond serves as a jewel. It istherefore preferable that the inclination of the facets on the crown bewithin a range of 31 degrees to 36 degrees against the plane making upthe table 2, as the inclination of the same of the diamond having theround brilliant cut is. It is also preferable that the inclination ofthe facets 8 on the pavilion 5 be within a range of 39 degrees to 42degrees. This is because of an empirically confirmed fact thatdetermining the inclinations of the facets on the crown and the mainfacets 8 to be within these angle ranges offers a greater amount ofreflected light coming out of the table 2, thus offering a diamond withmore brilliance.

It is also preferable in each of the above examples that the inclinationof facets other than the main facets 8, the facets being present on thepavilion 5 and located closer to the girdle than the main facets 8, belarger than the inclination of the main facets 8 by 0.5 degrees to 3.0degrees. This is because that if an inclination difference between theother facets and the main facets 8 is smaller than 0.5 degrees, theboundaries between the main facets 8 and the other facets becomeunclear, which makes creation of clear reflected light images Rimpossible. The inclination difference larger than 3.0 degrees, on theother hand, leads to the elongated shape of the diamond as a whole, inwhich case the beauty of the diamond's appearance is impaired.

In each of the above examples, the diamond serves as a jewel. Obviously,the present invention applies also to jewelry other than diamond. Insuch a case, the inclination of the facets on the crown and theinclination of the facets on the pavilion including the main facetsshould be adjusted properly according to the inherent refractive indexof a jewel to be used.

It is also preferable in each of the above examples that the size of thetable be 40% to 70% of the diameter of the diamond 1, i.e., the diameterof the girdle so that the whole of the reflected light images R on themain facets 8 can be visually recognized inside the table 2. A part ofan appeared pattern may become invisible near its center, i.e., near thecenter of the table 2 because of the limited size of the table 2, lightreflection on the diamond 1, etc. The present invention, however, seesno particular problem with such a case for the reason that such a partnear the center of the pattern is tiny or is regarded as a part of theappeared pattern itself, which means that the invisibility of the partdoes not have a particular effect on the aesthetic value of the appearedpattern. It is obvious from the viewpoint of the balanced form of thediamond 1 as a whole that the center of the plane of the table 2 shouldpreferably match an axis passing through the center of the curette 4.

In the above embodiment, the jewel having the girdle cut into a roundshape is described. According to the present invention, not only thejewel having the girdle cut into a round shape but also a jewel havingthe girdle cut into such a non-round shape as quadrangle and ellipse iscapable of causing a pattern to appear. This is because that accordingto the present invention, what pattern is to appear is determined by theshape and disposition of the main facets 8.

For example, as shown in FIG. 31, even if the girdle 6 of the diamond 1is quadrangular, the heart pattern of FIG. 8 appears inside the table 2when the shape and disposition of the main facets 8 are the same asthose of the diamond 1 that causes the heart pattern to appear. As shownin FIG. 32, even if the girdle 6 of the diamond 1 is elliptic, the heartpattern of FIG. 8 appears inside the table 2 when the shape anddisposition of the main facets 8 are the same as those of the diamond 1that causes the heart pattern to appear.

The above features of the present invention can be summarized asfollows.

The jewel according to the present invention includes the crown havingthe table, the pavilion having the curette, and the girdle formedbetween the crown and the pavilion.

The jewel according to the present invention includes four or more mainfacets formed on the pavilion. According to the present invention, themain facets are facets that produce reflected light images for causing adesired pattern to appear. The main facets are present on the pavilionand are of polygons (triangles, etc.) each having three or more angles.

Basically, each of the main facets of the present invention has one endin contact with the curette. However, in the cases of the peach blossompattern of FIG. 19 and the narcissus blossom pattern of FIG. 29,subfacets 14 with tiny cut lines are formed in contact with the curette4. In these exceptional cases, one end of each of the main facets 8 isnot in contact with the curette 4 because of the presence of thesubfacets 14. Nevertheless, in these cases, the main facets serve as thefacets that produce the reflected light images for causing the peachblossom pattern or narcissus blossom pattern to appear.

When the subfacets 14 are present on the pavilion 5 as in the abovecase, it is preferable that the inclination of the subfacets 14 besmaller than that of the main facets 8 by 2 degrees to 4 degrees. Thisis because that the subfacets 14 with the inclination smaller than thatof the main facets 8 by 2 degrees to 4 degrees prevents light reflectedon the subfacets 14 from entering the reflected light images R, allowingthe main facets 8 to produce the reflected light images R with enhancedclearness.

All the main facets of the present invention are formed such that ineach main facet, the distance between the curette and the apex of anangle of the main facet, the angle being closest to the girdle, is lessthan 90% of the distance between the curette and the girdle. Asdescribed above, the main facets are formed in this manner because ifthe main facets extend up to the position of the girdle, the front endsof reflected light images R that are closer to the girdle are concealedby the facets on the crown when the reflected light images R are seenfrom the table side, in which case an overall view of the reflectedlight images R cannot be visually recognized.

The main facets of the present invention are arranged such that they areline symmetry with respect to an axis of symmetry which is at least oneof lines passing through the curette to bisect the pavilion. This isbecause of a confirmed fact that unless at least one axis of symmetry ispresent, a meaningful pattern imitating something and excellingaesthetically cannot be caused to appear.

The jewel of the present invention may be defined as a jewel having thefollowing feature.

A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilionhas six or more main facets all or some of which are of polygons eachhaving three or more angles, wherein all the main facets are formed suchthat in each main facet, the distance between the curette and the apexof an angle of the main facet, the angle being closest to the girdle, isless than 90% of the distance between the curette and the girdle, andwherein the main facets are arranged such that they are line symmetrywith respect to an axis of symmetry which is at least one of linespassing through the curette to bisect the pavilion.

The jewel of the present invention may also be defined as a jewel havingthe following feature.

A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilionhas eight or more main facets all or some of which are of quadrangleseach having interior angles all different from each other or of polygonseach having five or more interior angels all different from each other,wherein all the main facets are formed such that in each main facet, thedistance between the curette and the apex of an angle of the main facet,the angle being closest to the girdle, is less than 90% of the distancebetween the curette and the girdle, and wherein the main facets arearranged such that they are line symmetry with respect to an axis ofsymmetry which is at least one of lines passing through the curette tobisect the pavilion.

The jewel capable of causing the pattern imitating the four-leave cloverto appear, which is included in the above examples, may be defined as ajewel having the following features.

A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilionhas ten main facets made up of five first main facets that are ofpentagons each having interior angels all different from each other andfive second main facets that are of pentagons line symmetrical to thepentagons serving as the first main facets, wherein the first mainfacets and the second main facets are arranged alternately on thepavilion, and wherein each of the pentagons serving as the first mainfacets and the second main surfaces is formed such that the distancebetween the curette and the apex of an angle of the pentagon, the anglebeing closest to the girdle, is less than 90% of the distance betweenthe curette and the girdle.

The jewel capable of causing the pattern imitating the peach blossom toappear and the jewel capable of causing the pattern imitating the cherryblossom to appear, which jewels are included in the above examples, mayeach be defined as a jewel having the following features.

A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilionhas ten main facets made up of five first main facets that are ofpentagons each having interior angels all different from each other andfive second main facets that are of pentagons line symmetrical to thepentagons serving as the first main facets, wherein the first mainfacets and the second main facets are arranged alternately on thepavilion, and wherein each of the pentagons serving as the first mainfacets and the second main surfaces is formed such that the distancebetween the curette and the apex of an angle of the pentagon, the anglebeing closest to the girdle, is less than 90% of the distance betweenthe curette and the girdle.

As described above, the present invention offers a jewel having novelcuts with excellent symmetry formed thereon, such cuts havingoriginality and excelling aesthetically.

EXPLANATION OF LETTERS AND NUMERALS

-   -   1 External view of a diamond having a round brilliant cut formed        thereon    -   2 Table    -   3 Crown    -   4 Curette    -   5 Pavilion    -   6 Girdle    -   7 Arrow    -   7 a Shaft portion of the arrow 7    -   7 b Arrowhead portion of the arrow 7    -   8 Main facet    -   8 a Main facet where a first reflection point 11 is present    -   8 b Main facet where a second reflection point 12 is present    -   8 p Apex of an angle of the main facet 8, the angle being        closest to the girdle 6    -   9 Lower girdle facet    -   10 Facet    -   11 First reflection point    -   12 Second reflection point    -   13 Heart pattern    -   14 Subfacet    -   15 Incoming light    -   16 Reflected light image

1. A jewel comprising: a crown having a table; a pavilion having acurette; and a girdle formed into a round cut between the crown and thepavilion, wherein the pavilion has eight or more main facets all or someof which are of quadrangles each having interior angles all differentfrom each other or of polygons each having five or more interior anglesall different from each other, wherein all the main facets are formedsuch that in each main facet, a distance between the curette and an apexof an angle of the main facet, the angle being closest to the girdle, isless than 90% of the distance between the curette and the girdle, andwherein the main facets are arranged such that they are line symmetrywith respect to an axis of symmetry which is at least one of linespassing through the curette to bisect the pavilion.
 2. A jewelcomprising: a crown having a table; a pavilion having a curette; and agirdle formed between the crown and the pavilion, wherein the pavilionhas eight main facets made up of four first main facets that are ofpentagons each having interior angels all different from each other andfour second main facets that are of pentagons line symmetrical to thepentagons serving as the first main facets, wherein the first mainfacets and the second main facets are arranged alternately on thepavilion, and wherein each of the pentagons serving as the first mainfacets and the second main surfaces is formed such that a distancebetween the curette and an apex of an angle of the pentagon, the anglebeing closest to the girdle, is less than 90% of the distance betweenthe curette and the girdle.
 3. A jewel comprising: a crown having atable; a pavilion having a curette; and a girdle formed between thecrown and the pavilion, wherein the pavilion has ten main facets made upof five first main facets that are of pentagons each having interiorangels all different from each other and five second main facets thatare of pentagons line symmetrical to the pentagons serving as the firstmain facets, wherein the first main facets and the second main facetsare arranged alternately on the pavilion, and wherein each of thepentagons serving as the first main facets and the second main surfacesis formed such that a distance between the curette and an apex of anangle of the pentagon, the angle being closest to the girdle, is lessthan 90% of the distance between the curette and the girdle.
 4. Thejewel according to claim 1, wherein the jewel is a diamond.
 5. The jewelaccording to claim 2, wherein the jewel is a diamond.
 6. The jewelaccording to claim 3, wherein the jewel is a diamond.